| rtprio.1 (3091) | rtprio.1 (3291) |
|---|---|
| 1.\" 2.\" Copyright (c) 1994, Henrik Vestergaard Draboel 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 20 unchanged lines hidden (view full) --- 29.\" SUCH DAMAGE. 30.\" 31.\" $Id: rtprio.1,v 1.1 1994/09/01 12:05:13 davidg Exp $ 32.\" 33.Dd July 23, 1994 34.Dt RTPRIO 1 35.Os 36.Sh NAME | 1.\" 2.\" Copyright (c) 1994, Henrik Vestergaard Draboel 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 20 unchanged lines hidden (view full) --- 29.\" SUCH DAMAGE. 30.\" 31.\" $Id: rtprio.1,v 1.1 1994/09/01 12:05:13 davidg Exp $ 32.\" 33.Dd July 23, 1994 34.Dt RTPRIO 1 35.Os 36.Sh NAME |
| 37.Nm rtprio 38.Nd execute, examine or modify a process's realtime scheduling priority | 37.Nm rtprio , 38.Nm idprio 39.Nd execute, examine or modify a utilitys or process realtime 40or idletime scheduling priority |
| 39.Sh SYNOPSIS 40 | 41.Sh SYNOPSIS 42 |
| 41.Nm rtprio 42.Nm rtprio | 43.Nm [id|rt]prio 44.Nm [id|rt]prio |
| 43.Ar pid | 45.Ar pid |
| 44.Nm rtprio | 46.Nm [id|rt]prio |
| 45.Ar priority 46.Ar command 47.Op args | 47.Ar priority 48.Ar command 49.Op args |
| 48.Nm rtprio | 50.Nm [id|rt]prio |
| 49.Ar priority 50.Ar -pid | 51.Ar priority 52.Ar -pid |
| 51.Nm rtprio | 53.Nm [id|rt]prio |
| 52.Ar -t 53.Ar command 54.Op args | 54.Ar -t 55.Ar command 56.Op args |
| 55.Nm rtprio | 57.Nm [id|rt]prio |
| 56.Ar -t 57.Ar -pid 58.Sh DESCRIPTION 59.Nm Rtprio | 58.Ar -t 59.Ar -pid 60.Sh DESCRIPTION 61.Nm Rtprio |
| 60is used for controlling realtime process scheduling. A process with a 61realtime priority is not subject to priority degradation, and will only 62be preempted by another process of equal or higher realtime priority. | 62is used for controlling realtime process scheduling. |
| 63 | 63 |
| 64.Nm Rtprio 65called without arguments, will return the realtime priority | 64.Nm Idprio 65is used for controlling idletime process scheduling, and can be called 66with the same options as 67.Nm Rtprio . 68 69A process with a realtime priority is not subject to priority 70degradation, and will only be preempted by another process of equal or 71higher realtime priority. 72 73A process with an idle priority will run only when no other 74process is runnable and then only if it's idle priority is equal or 75greater than all other runnable idle priority processes. 76 77.Nm Rtprio 78or 79.Nm Idprio 80when called without arguments will return the realtime priority |
| 66of the current process. 67 68If 69.Nm rtprio 70is called with 1 argument, it will return the realtime priority 71of the process with the specified 72.Ar pid . 73 74If 75.Ar priority 76is specified, the process or program is run at that realtime priority. 77If 78.Ar -t 79is specified, the process or program is run as a normal (non-realtime) 80process. 81 82If 83.Ar -pid | 81of the current process. 82 83If 84.Nm rtprio 85is called with 1 argument, it will return the realtime priority 86of the process with the specified 87.Ar pid . 88 89If 90.Ar priority 91is specified, the process or program is run at that realtime priority. 92If 93.Ar -t 94is specified, the process or program is run as a normal (non-realtime) 95process. 96 97If 98.Ar -pid |
| 84is specified, the process with that pid will be modified, else 85if | 99is specified, the process with the process identifier "pid" will be 100modified, else if |
| 86.Ar command 87is specified, that program is run with its arguments. 88 89.Ar Priority | 101.Ar command 102is specified, that program is run with its arguments. 103 104.Ar Priority |
| 90is an integer between 0 (RTPRIO_MIN) and 31 (RTPRIO_MAX). 0 is the | 105is an integer between 0 and RTP_PRIO_MAX (usually 31). 0 is the |
| 91highest priority 92 93.Ar Pid 94of 0 means "the current process". 95 | 106highest priority 107 108.Ar Pid 109of 0 means "the current process". 110 |
| 96Only root is allowed to set realtime priorities. | 111Only root is allowed to set realtime priorities. Non-root processes may 112set idle priority levels for the current process only. |
| 97.Sh RETURN VALUE | 113.Sh RETURN VALUE |
| 114If |
|
| 98.Nm rtprio | 115.Nm rtprio |
| 99returns the (new) realtime priority of the process (see rtprio(2)), or 100-1 for all usage errors. | 116execute a command, the exit value is that of the command executed. 117In all other cases, 118.Nm 119exits with 0 for success and 1 for all other errors. |
| 101.Sh EXAMPLES 102.\LP 103 104To see which realtime priority the current process is at: 105.Bd -literal -offset indent -compact 106\fBrtprio\fP 107.Ed 108 --- 17 unchanged lines hidden (view full) --- 126 127.\.LP 128To run \fItcpdump\fP without realtime priority: 129.Bd -literal -offset indent -compact 130\fBrtprio -t tcpdump\fP 131.Ed 132 133.\.LP | 120.Sh EXAMPLES 121.\LP 122 123To see which realtime priority the current process is at: 124.Bd -literal -offset indent -compact 125\fBrtprio\fP 126.Ed 127 --- 17 unchanged lines hidden (view full) --- 145 146.\.LP 147To run \fItcpdump\fP without realtime priority: 148.Bd -literal -offset indent -compact 149\fBrtprio -t tcpdump\fP 150.Ed 151 152.\.LP |
| 134To change the realtime priority of process \fI1423\fP to RTRIO_RTOFF 135(no realtime): | 153To change the realtime priority of process \fI1423\fP to RTP_PRIO_NORMAL 154(non-realtime/"normal" priority): |
| 136.Bd -literal -offset indent -compact 137\fBrtprio -t -1423\fP 138.Ed | 155.Bd -literal -offset indent -compact 156\fBrtprio -t -1423\fP 157.Ed |
| 139.Sh DIAGNOSTICS 140The 141.Nm rtprio 142utility shall exit with value of the (new) realtime priority of the 143program. | 158 159.\.LP 160To make depend while not disturbing other machine usage: 161.Bd -literal -offset indent -compact 162\fBidprio 31 make depend\fP 163.Ed |
| 144.Sh SEE ALSO 145.Xr rtprio 2 , 146.Xr nice 1 , 147.Xr ps 1 , 148.Xr nice 2 , 149.Xr renice 8 150.Sh HISTORY 151The 152.Nm rtprio 153utility appeared in 154FreeBSD 2.0, 155but is similar to the HP-UX version. | 164.Sh SEE ALSO 165.Xr rtprio 2 , 166.Xr nice 1 , 167.Xr ps 1 , 168.Xr nice 2 , 169.Xr renice 8 170.Sh HISTORY 171The 172.Nm rtprio 173utility appeared in 174FreeBSD 2.0, 175but is similar to the HP-UX version. |
| 176.Sh CAVEATS 177You can lock yourself out of the system by placing a cpu-heavy 178process in a realtime priority. |
|
| 156.Sh BUGS | 179.Sh BUGS |
| 157You can lock yourself out of the system by placing a cpu-intensive 158process into realtime priority. 159 | |
| 160There is no way to set/view the realtime priority of process 0 161(swapper) (see ps(1)). 162 | 180There is no way to set/view the realtime priority of process 0 181(swapper) (see ps(1)). 182 |
| 183There is in 184FreeBSD 185no way to ensure that a process page is present in memory therefore 186the process may be stopped for pagein. (See mprotect(2), madvise(2)). 187 188Under 189FreeBSD 190system calls are currently never preempted, therefore non-realtime 191processes can starve realtime procesess, or idletime processes can 192starve normal priority processes. 193 |
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| 163Others ... 164.Sh AUTHOR | 194Others ... 195.Sh AUTHOR |
| 165Henrik Vestergaard Draboel - hvd@terry.ping.dk | 196Henrik Vestergaard Draboel - hvd@terry.ping.dk is the original author. This 197implementation in FreeBSD was substantially rewritten by David Greenman. |